1. Field of the Invention
The present invention relates to a varistor and, more particularly, to a varistor with a varistor element body consisting primarily of ZnO (zinc oxide), and a method of producing the varistor.
2. Related Background Art
One of the known varistors of this type is a varistor having a varistor element body, and external electrodes disposed on the varistor element body (e.g., reference is made to Japanese Patent Application Laid-Open No. 6-120007). In the varistor described in the Laid-Open No. 6-120007, the varistor element body contains ZnO as a principal component, and contains Bi as a material to develop nonlinear voltage-current characteristics (hereinafter referred to as “varistor characteristics”).
The Laid-Open No. 6-120007 also discloses the following method of producing the varistor. First, the varistor element body is made by laminating ceramic green sheets in which conductor patterns to become internal electrodes are formed and ceramic green sheets without any conductor pattern, in a desired order and then firing the sheets. An electroconductive paste is applied onto the resultant varistor element body and thereafter baked to form the external electrodes.